The primary objective of the Biostatistics and Data Management Core (BDMC) of the CCNMD is to provide CCNMD investigators with expertise in study design and planning, project implementation and data management, statistical methods and statistical analysis, including interpretation and dissemination of results, and consultation and teaching. The BDMC draws on the expertise of its two Ph.D. biostatisticians, its data manager, and other biostatisticians elsewhere in the Center, department, and the University. Study design and planning includes choice and focus of the research question, the turning of such questions into testable hypotheses involving variables that are measurable and capable of use in testing the hypotheses, design of the studies, plans for statistical analysis, and power and sample size calculations. Project implementation includes service of the core director on the Steering Committee and data management includes design of new forms, quality control and testing of existing forms, design and testing of the data entry and data management system, continuing and ongoing consultation with and meeting with project directors, quality control and quality assurance, and interim administrative reports. It further includes statistical and data consultation if new issues arise during the implementation of the projects. Statistical methods include the detailed design of the statistical analyses of the data in each project, as well as the design of new hypotheses to consider in each project, which depend on results in other projects. Data from each project may suggest hypotheses to test using data from the other projects. It further includes planned statistical analyses of data from all projects, as well as exploratory analyses suggested by the data, which need to be conducted in a rigorous manner, which controls for multiple comparisons. Interpretation and dissemination of results includes working with investigators to ensure that interpretation of results do not go beyond that which can be supported by the data, authoring or coauthoring the results sections of reports and manuscripts, and working with investigators in writing discussion sections. Consultation and teaching include ongoing consultation with project investigators in order to ensure that data are collected and entered in a timely and accurate manner, and educating investigators, residents, and fellows about statistical methodological issues important to these projects, and to psychiatric and other medical research projects more generally. BDMC personnel will present a series of seminars on research methodology and statistical methods to investigators, residents, fellows, and students.